Highly abrasion-resistant tape for binding cable trees in motor vehicles

ABSTRACT

The invention relates to a highly abrasion-resistant tape for binding cable trees, in particular in motor vehicles. Said strip consists of a support, comprising a first cover layer A and a second cover layer B. An intermediate layer C is situated between the cover layers A and B, said intermediate layer being permanently fixed to the entire surface area of the cover layers A and B. According to the invention, the cover layers A and B consist of a woven or knitted fabric and the intermediate layer C consists of a visco-elastic adhesive, preferably a pressure-sensitive adhesive, or a double sided adhesive tape.

This application is a 371 of PCT/EP2005/002300, filed Mar. 4, 2005,which claims foreign priority benefit under 35 U.S.C. § 119 of theGerman Patent Application No. 10 2004 011 223.1 filed Mar. 4, 2004.

The invention relates to a highly abrasion-resistant tape which can beused in particular for bandaging cable harnesses in automobiles.

In many segments of industry, bundles composed of a multiplicity ofelectrical lines are wrapped either before installation or when alreadymounted, in order to reduce the space taken up by the bundle of lines,by means of bandaging, and also to obtain protective functions. Withsheet adhesive tapes a certain protection against ingress of liquid isachieved; with airy and bulky adhesive tapes based on thick nonwovens orfoam backings, insulating properties are obtained; and when stable,abrasion-resistant backing materials are used a protective functionagainst scuffing and rubbing is achieved.

Particularly the protective function with respect to scuffing, rubbing,grinding on sharp edges and burrs, etc., summarized here under theconcept of abrasion resistance, is increasing in significance. The sharpedges, burrs and weld points, etc., that come about as a result ofproduction operations are increasingly not having their sharpnessremoved by complicated post-production work, since such work entails anadditional operation and increased costs. This is so in particular inthe case of the untreated bodies in the automobile industry, but also inother segments too, such as in the case of washing machines, vibratingmachines such as compressors and the like, for example. Cable strandswhich run in such segments and which are scuffed by vibration, relativemovements and the like on such sharp points are therefore at potentialrisk of destruction of the protective sheath. This protective sheath maybe the additional wound bandaging, or else may be the insulation aroundthe copper cable itself. In that case the result would be a shortcircuit with complete functional failure and destruction ofelectrical/electronic components, possibly going as far as a fire, withthe attendant risks of damage to equipment and people.

In order to minimize potential hazards of this kind it is the case notonly that normal wrapping tapes are used to bandage the cable strands atcritical points but also that additional precautions are taken. Eitherspecialty adhesive tapes are used or particular protective componentsare employed. These components may, for example, be cable ducts made ofwear-resistant polymers such as polyamide or fluted tubes or braidedhoses of polyester or nylon, all components which are unfavorable fromthe standpoints of cost, separate logistics and complexity of handlingduring assembly. In the case of the assembly of fluted tubes and cableducts, for example, considerable effort is required for attaching thelengthy tube systems and fixing them reliably to the cable bundle and/orto the body, in order to prevent slipping. Additionally, separatemeasures may be necessary for preventing rattling, since the lines inthe tube systems rarely lie flush against them and in the event ofvibrations they therefore produce rattling noises with the hardmaterials of the tubes.

Specialty adhesive tapes as well are used in segments involvingincreased abrasion protection and scuff protection. Adhesive tapes forthe wrapping of cable sets or similar elongated systems with additionalfunctionalities are known in the prior art and in some cases are alsoutilized commercially: EP 1 136 535 A1 includes in its description amultilayer adhesive tape with a soundproofing effect, composed of avelour and a nontextile interply, said interply being either a film or adirectly applied, nonadhesive plastic or foam coating. This interlayerserves to stabilize the velour against warping and as a barrier layerfor preventing penetration of the adhesive, applied by knife coating,into the velour backing. With an adhesive tape of this kind the desiredabrasion protection is low and is achieved solely by the outer layer ofthe velour and the outwardly pointing velour loops.

Sound insulation is the sole purpose of the adhesive tape described inDE 199 10 730 A1, which is composed of a laminate, a sound insulationlayer (velour or foam) and a web, produced using hotmelt adhesive,melting powder or a transfer fixative. The use of the very expensivevelour backing comprising the polymer material polyester or polyamide isalso employed in other applications which describe adhesive tapes with apronounced antirattle function (DE 299 00 294 U1, DE 299 16 616 U1 andDE 101 02 927 A1). In all cases the resulting adhesive tapes have a highprice and in terms of abrasion protection do not meet very highrequirements.

A construction similar to that of EP 1 136 535 A1 is possessed by DE 10149 975 A1. In this case an adhesive tape for protecting articles againstabrasion and rattling is described that has a two-layer constructioncomprising a textile layer and a film applied by calendering. Woven orweb, as the textile layer, and PVC films in particular are firmly andpermanently connected to one another here, without the use of adhesives,by calendering under pressure and heat. The textile layer is arrangedfacing away from the article to be protected.

WO 00/13894 A1 describes a scuff protection device as edge protectionfor sharp-edged components such as sheet steel bodywork burrs, the scuffprotection being adhered in such a manner as to engage around suchareas. The scuff protection is composed of a textile backing layer (madeof velour or a needle felt, for example) and of a protective film,preferably made of thermoplastic polyurethane polymer, which is appliedon the side of the scuffing sides, and also of an adhesive layer whichis applied on the side of the component and has a release paper lining.Textile backing layer and protective film are joined to one another viaa thin adhesive bond, the adhesive being applied only in selected areasin the form of a heat-activable adhesive web, powder or film. Thiscomplicated assembly is lined with release paper, used in appropriatecut-to-size shapes, and is therefore unsuitable for the generalprotective wrapping of cable harnesses. The protective device of thisinvention does not actively protect the cable harness; instead, whereneeded, sharp-edged parts are locally masked from their surroundings asa kind of passive cable loom protection.

DE 100 42 732 A1 describes an adhesive tape for the spiral wrapping ofelongate products such as cable looms, for example, where a stripecoating which does not extend over the full area of the backing,preferably a textile backing, produces reduced adhesion of the wrappingtape to the lines and hence improved mobility and bendability of thecable loom as a whole. Inventive adhesive tapes of that kind, however,do not offer any particular abrasion protection, but serve solely forthe flexibilization of the cable loom.

An adhesive tape with a combination of noise reduction andfrictional-stress protection properties is described in DE 101 13 425A1. Even at the required basis mass of the web backing with verticalpole folds, of more than 200 g/m², the protective effects obtained areonly in the middle range for attenuation, and in particular againstabrasion, as was already known even from EP 0 995 782 A1 and also EP 0995 783 A1. Similar comments are also true of DE 100 39 983 A1, which inone specific embodiment describes a textile assembly composed of ascuff-resistant web and a textile sheetlike structure, which is producedwithout the use of a laminating adhesive or the like, solely byhydroentanglement. While the textile sheetlike structure impartsadditional attenuating or reinforcing properties to the assembly, theabrasion resistances for the scuff-resistant hydroentangled base web,composed of stable fibers, is seen as being fairly low for a basis massof not more than 200 g/m². Further references, and particularly specificdetails regarding scuff resistances, are absent from all of theprotective rights referred to above.

Besides the stitchbonded web mentioned in the cited publication, thereare further backings which are used in adhesive tapes for cable harnessbandaging.

DE 44 42 092 C1 describes one such stitchbond-based adhesive tape, whichis coated on the reverse of the backing. DE 44 42 093 C1 is based on theuse of a web as backing for an adhesive tape, the web being formed bythe formation of loops from the fibers of the web reinforced cross-laidfiber web, in other words a web which is known to the skilled workerunder the name Malifleece. DE 44 42 507 C1 discloses an adhesive tapefor cable bandaging but bases it on so-called Kunit or Multiknit webs.

One extremely complicated and high-cost multilayer assembly is disclosedby EP 0 886 357 A1 and EP 0 886 358 A1. In that case a PET spunbondedweb, a PET formed-loop knit and, where appropriate, a felt or foam plyare each bonded to a laminating layer. This assembly of up to fivelayers, which is already complicated, is additionally provided partiallywith the two necessary components of a touch-and-close fastening systemand one or more self-adhesive strips lined by protective paper. From aneconomic standpoint, systems of this kind with a high abrasionprotection function are practicable only at a few selected sites, butnot as general wrapping tapes for cable looms or other elongatedarticles.

With similar complexity, DE 298 23 462 EU1 describes, as protectivecladding for preventing rattling noises for line systems, a wrappingtape featuring a backing assembly comprising at least two textilelayers, this tape being said additionally to exhibit high abrasionresistance and chafing resistance. The outer layer is composed of a warpknit velour with highly raised velour loops, which in certain areas isconnected to a web, preferably a needlefelt web, by means of aheat-activable laminating adhesive, with a coat weight of from 10 to 30g/m². At about 1.5 to 4 mm, the sheathing is too thick, when applied,for numerous automobile applications and, as a result, cannot be used atnarrow points.

In summary it is possible to observe that there are a multiplicity ofattempted solutions in which, preferably, the very costly textilebacking material, velour, is responsible, in conjunction with at leastone further textile or nontextile sheetlike structure, for theparticular abrasion protection and/or antirattle protection (describedin detail in DE 298 23 462 EU1). The backing assembly is produced eitherwithout an adhesive layer or else by means of a particularheat-activable laminating adhesive, frequently used only in selectedareas. The sole purpose of self-adhesive compositions is to produce anadhesive tape, as a separate layer from this backing assembly. Owing tothe use of the knit velour, adhesive tapes of this kind are not onlyvery expensive but also, as a result of the loop structure, are so thickthat specialty wrapping tapes of this kind cannot be used in the normaloverlapping spiral wrapping or in longitudinal sheathing, owing to thescant installation spaces that are available.

It is an object of the invention to achieve a marked improvement overthe state of the art and to provide a tape which combines thepossibility for bandaging individual lines to form cable looms with highprotection against mechanical damage caused by scuffing and rubbing onsharp edges, burrs, weld spots, etc. This tape, preferably adhesivetape, ought to be suitable not only for the standard wrapping techniqueswith overlapping or open spiral wrapping around the bundle of lines butalso for longitudinal application by means of applicators, such as aredescribed in EP 1 008 152 A1, for example, or in the form of specialprocessing versions, particularly in accordance with DE 100 36 805 A1.In the special form with only striplike adhesive coating in thelongitudinal direction at the edges of the backing material, inaccordance with DE 100 42 732 A1, the backing material of the inventionought also to lead to innovative, highly abrasion-resistant cablewrapping tapes which combine bandaging function and abrasion protectionfunction in the preferred adhesive tape.

An established method of determining the abrasion resistance ofprotection systems in vehicle electrics is the international standardISO 6722, section 9.3 “scrape abrasion test” (issued April 2002). Inthis test the test specimen (for example, the insulated copper line orelse the wrapping tape adhered to a metal mandrel) is exposed to a thinsteel wire with defined scrape geometries and under a defined weightload, until the protective sheath has been rubbed through and, as aresult of short circuiting, the counter which runs at the same timecomes to a stop.

Unless indicated otherwise, all details relating to abrasion resistancerefer to this ISO 6722 method. The adhesive tape is for this purposeadhered in a single ply in the longitudinal direction on a metal mandrel10 mm in diameter; the scraping motion takes place centrally on theadhesive tape under a weight load of 7 N. The rubbing body used is asteel wire complying with ISO 8458-2, 0.45 mm in diameter. The parameterfor the abrasion resistance that is reported is the number of scrapesuntil short circuiting. In cases of very high scuff resistances, themass that is applied can be increased in order to reduce the measurementtime and the number of scrapes. In this case an applied weight of 10 Nhas proven favorable.

The invention accordingly provides a highly abrasion-resistant tape forbandaging cable harnesses, in particular in automobiles, comprising abacking having a first outer layer A and a second outer layer B, with

-   -   an interlayer C located between and firmly connected, in each        case, over its entire surface, to the outer layers A and B,    -   the outer layers A and B being composed of a woven fabric or        formed-loop knit,    -   the interlayer C being composed of a viscoelastic adhesive,        preferably self-adhesive, or a double-sided adhesive tape.

In a first advantageous embodiment of the invention the viscoelasticadhesive or the adhesives for the double-sided adhesive tape areself-adhesive compounds based on natural rubber, synthetic rubber,polyacrylates or silicones.

Surprisingly it is found that when a multi-ply system is produced inaccordance with the invention the abrasion resistance of the overallassembly turns out to be much higher than the sum of the abrasionresistances of the individual plies, thereby achieving a considerableincrease in the protective effect against rubbing and scuffing exposureswithout the need to take special protection measures. With the inventiveconstruction of the tape it is possible to produce a combination of thebandaging possibilities of a normal wrapping tape with the abrasionprotection of specialty systems such as TwistTubes®, braided hoses,flexible corrugated tubes and the like. For this purpose it is necessaryto select the kind of composite construction for the backing materialthat is described below, and in this context the stated embodimentsshould be regarded only as examples.

Preferably the abrasion resistance of the backing (measured inaccordance with ISO 6722, Section 9.3 “Scrape abrasion resistance”) isat least 150% of the sum of the abrasion resistances of the individualplies.

The system in question is a multi-ply system composed of two identicalor different outer layers A and B, at least one per se featuringfavorable abrasion resistance, such as, for example, films, nonwovens,formed-loop knits, wovens, velour, etc., and which is composed ofcorresponding materials, and at least one interlayer C, which firstlyprovides the permanent connection between the outer layers A and B butis also designed such that it is able to absorb and “eliminate” forcesand energies which occur in the course of rubbing and scuffing motions.This specific energy elimination may denote the mechanical energy beingpassed onto other parts in the tape or its surroundings or else maydenote its at least partial conversion into heat or the like. Thisprevents the original mechanical energy destroying the outer layers, bybeing converted into other forms of energy or else transmitted to areasof the tape at which it causes no damage or else lesser damage thandirectly on the outer layers. Accordingly the functional capacity of thetape as a wrapping tape and protective sheath is prolonged, so that inmany cases there is no need for additional, expensive andlabor-intensive protection systems.

In the prior art, use is also made in many cases of multi-ply compositesystems in which the interlayer C does not effect the aforementionedfunctionality but is only intended to produce the connection between twoplies A and B. The interlayers are typical laminating adhesives, in theform for example of heat-activable adhesive webs or in similar forms.These systems are characterized in that they are applied at very lowgrammages/thicknesses in order, by adhesion to the two plies A and B, toproduce a permanent and solid contact, without significantly increasingthe production costs. After they have cooled, heat-activablethermoplastics of this kind do not have self-adhesive properties. Thecoatweights for laminating adhesives of this kind are normally situatedwithin the lower region of the range from 10 to 30 g/m², whereas atcoatweights in the upper range such composites can become boardy andpossibly too stiff for a wrapping tape. In many cases, deliberately oras an inevitable result of choice of the laminating adhesive technology,only partial formation of a connection between the plies is obtained.Reference may be made here, by way of example, to the abrasionprotection system composed of a nylon warp velour and a polyester needlefelt in accordance with VW standard part number N 908 809, where thebacking assembly is laminated together by a nonself-adhesiveheat-activable nylon spun bonded web with a basis mass of 17 g/m².

In contrast, the inventive interlayer C is characterized in that it hasa considerably greater thickness and/or mass between the outer plies Aand B and in terms of the material used and/or the construction iscapable of dissipating or converting externally incident forces andenergies from friction, scuffing, vibrations, etc. Particularly suitablehere are rubber-elastic as viscoelastic layers such as thick adhesivelayers of natural or synthetic rubber or polyacrylates. Generallyspeaking, viscoelastic systems such as are used in self-adhesivecompositions are particularly suitable for use as an interlayer of thiskind.

Even systems which are already of multi-ply construction per se aresuitable as interlayers according to the invention. Known double-sidedadhesive tapes for carpet laying, for example, have not only an internalsheetlike support backing but also thick adhesive layers on both outersides. Suitable backings, as well as films, foamed systems, nonwovens,formed-loop knits and parallelized filaments, include open woven fabricsin particular. Conceivable adhesives include all known systems such-asacrylates, silicones, synthetic rubbers and also, in particular, naturalrubber and formulations derived therefrom. Where double-sided adhesivetapes of this kind, such as the known carpet-laying tape tesafix® 4964,for example, are placed between the outer layers A and B, a significantincrease is obtained in the abrasion resistance, which is markedlyhigher than the sum of the individual layers.

Where the adhesive tapes selected for the interlayer C are double-sidedadhesive tapes which have, as a support backing centrally between thetwo outer layers of adhesive, a coherent, impervious sheetlike structuresuch as, for example, a flexible film, the highly abrasion-resistantwrapping tape of the invention acquires an additional property, which incertain cases is also advantageous on its own and can lead to the use ofthe product. Particularly in areas in which strands of lead can comeinto contact with aggressive chemicals, the bandaging or sheathingthereof with an adhesive tape of this kind would result in a substantialbarrier effect with respect to said chemicals. The film acts as abarrier, for example, to service fluids such as gasoline, lubricatingoils, antifreeze, and the like in the engine compartment of motorvehicles. This is advantageous because, as is known, quite a few ofthese service fluids can damage the internally located lead insulation.The coherent barrier layer can either be introduced as a backing filmvia the double-sided adhesive tape into the interlayer or else producedseparately during the operation of producing the composite backing, byproducing the interlayer in two plies from the same or different layersof adhesive, an appropriate film being inserted between these two plies.

For the films it is possible to use resistant polymers such as PVC,polyethylene, polypropylene, polyesters, and other high-performancepolymers; in particular, elastic and flexible films in a thickness of 5to 150 μm, especially 15 to 50 μm, are suitable for this purpose.

Without these figures being regarded as a sharp exclusion limit, theentire interlayer C ought to have a thickness of about 0.05 to 2 mm,with interply thicknesses of from 0.05 to 1.0 mm being appropriate inview of the actual upper limit on the thickness of the overall adhesivetape for bandaging applications of elongated products such as cablestrands, for example, which in the normal case is about 1 to 1.5 mm.

For an inventive improvement in abrasion resistance, suitable basismasses for the interlayer C are from 40 to 600 g/m², in particular from50 to 300 g/m².

Backing assemblies of this kind in accordance with the invention are notonly notable for very high abrasion and scuff resistances but also havesoundproofing properties, so that depending on the field of use they canbe used not only as a protection system against mechanical loads butalso as an antirattle tape. Specifically with cable harnesses inmachines or automobiles it is frequently necessary to combine abrasionprotection directly with antirattle requirements. A moving cable strandmay on the one hand become scuffed on sharp edges and burrs but may alsogenerate rattling noises in the case of vibrations and counterstriking.If the wrapping tapes used for cable bandaging are then capable ofactively suppressing or reducing the occurrence of noise, there is noneed for additional, high-cost soundproofing measures.

The backing assemblies of the invention, with a thick interlayer ofviscoelastic adhesive and/or a double-sided adhesive tape, result in acertain sound damping and noise suppression, which can be boosted byadditionally integrating in the interlayer C a “voluminous” sheetlikestructure such as, for example, a nonwoven, formed-loop knit, foamedfilm or foam.

In a further advantageous embodiment of the invention the backing iscoated at least on one side with a self-adhesive compound.

This coating takes place on the open side of the outer layer A or theopen side of the outer layer B.

In order to produce a self-adhesive tape from the assembly backing it ispossible to have recourse to any of the known adhesive systems. Besidesnatural rubber or synthetic rubber based adhesives it is also possibleto use silicone adhesives and, in particular, polyacrylate adhesives. Onaccount of their particular suitability as the adhesive for wrappingtapes for automobile cable sets, with respect to the absence of foggingand also the outstanding compatibility with PVC and PVC-free coreinsulation, preference is given to solvent-free acrylate hotmelts, asdescribed in more detail in DE 198 07 752 A1 and also in DE 100 11 788A1. The adhesive coat weights should be adapted to the respectiveassembly systems in respect of the roughness and absorbency of thesurface to be coated, and are in the range between 40 to 100 g/m² forsmooth, nonabsorbent outer layers or else up to 300 g/m² for open,textured outer layers, with 50 to 150 g/m² being regarded as sufficientin the normal case. As coating technology for backing materials of thiskind it is possible to have recourse to known systems, with appropriateprocesses for open, absorbent textiles being those which allow adhesivesof high viscosity to be applied without pressure, such as the nozzlecoating of hotmelt adhesives or their application by transfer from anantiadhesive carrier cloth or release liner to the backing assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in greater detail with reference tothe drawings, wherein:

FIG. 1 is a schematic depicting a first backing assembly; and

FIG. 2 is a schematic depicting a second and a third backing assembly.

One advantageous form of a backing assembly of the invention can beproduced from two outer layers and a thick, viscoelastic interlayer bylaminating together two identical or different backing materials, coatedon one side with adhesive, or in different widths, with the adhesivesides facing one another and with an offset, so that at the edges ofeach side a narrow strip of adhesive remains open and tacky.Constructions of this kind have already been described in DE 100 42 732A1 or DE 37 33 841 A1, although not for use in highly abrasion-resistantadhesive tapes. In the simplest case, therefore, it is possible toemploy two suitable standard adhesive tapes which are combined in theabovementioned configuration and which thereby form a highlyabrasion-resistant adhesive tape which is suitable in particular for thelongitudinal sheathing of elongate products in accordance with DE 100 36805 A1, as shown in FIG. 1.

If the two adhesive strips at the edge are to be oriented toward thesame side, a further possibility is a slightly altered, simplerconstruction, which leads, however, to a reduction in the abrasionprotection function, since the viscoelastic interlayer is reduced in itspower, as shown in FIG. 2. Which of the two versions is used depends ineach specific case on the economic and technical requirements.

The narrower backing strip for partial lining may therefore, as in theabove case, be an adhesive tape made up of backing and self-adhesivecompound, or else just a sheetlike structure such as a film or a textilebacking, if the self-adhesive layer of the wide strip is alreadysufficiently dimensioned.

Through an appropriate selection of the two components, in other words,in this case, the two self-adhesive tapes, the adhesive tape can bevaried within wide ranges for longitudinal sheathing applications. Byway of the type of backing materials used it is possible to select theabrasion resistance and thermal stability, damping properties and alsocolor and appearance of the outer ply. The interlayer of the inventionis achieved through the nature and amount of the respective adhesivetape coating.

The inventive concept therefore further embraces an elongate product,such as a cable harness in particular, wrapped with an adhesive tape ofthe invention, and also a vehicle comprising the wrapped elongateproduct.

As outer layers suitability is possessed in principle by all sheetlikestructures which offer a suitable scuff resistance and surface area asto be appropriate for applications of this kind in the automobilesegment, especially woven fabrics, formed-loop knitted fabrics, velours,nonwovens and similar textile materials. Fabrics which have provenparticularly suitable are closely woven filament fabrics of polyester ornylon, or else of glass fibers or high-performance plastics such ascarbon fibers, with a weave construction of 40 to 50 threads per cm inthe warp direction and 20 to 30 threads per cm in the fill direction.Woven PET fabrics of this kind with a basis weight of from 70 to 150g/m² have already been used for some time in wrapping tapes in theengine compartment, are temperature-and age-resistant and are known tohave a mean abrasion resistance of approximately 300 to 1000 scrapecycles in accordance with ISO 6722 (mandrel diameter 10 mm, 10 N appliedweight, 0.45 mm steel wire) (see table 1): TABLE 1 Adhesive tapeAbrasion resistance Woven PET fabric (130 g/m²) with rubber  500 to 1000cycles compound Stitchbonded PET web (80 g/m²) with rubber   20 to 100cycles compound 0.1 μm PVC film with rubber compound    1 to 50 cyclesTwistTube = braided PET hose (without adhesive) 2000 to 5000 cycles

If it is assumed in a first approximation that when a woven filamentfabric of this kind is used in a double ply with from 5 to 30 g/m² of a(partially applied) laminating adhesive in between the abrasionresistance is doubled, then the effect when using an interply of 50 g/m²or more of a suitable viscoelastic adhesive layer—a UV-crosslinkedhotmelt acrylate adhesive or a natural rubber adhesive, for example—issurprisingly positive.

The abrasion resistance of a composite system of this kind issignificantly higher than the sum of the outer plies (table 2). TABLE 2Construction of the backing assembly from 2 woven PET filament fabricsAbrasion resistance (125 g/m²) and as interlayer C (7 N applied weight)A none 5130 cycles B  30 g/m² laminating adhesive 5310 cycles C 120 g/m²acrylate hotmelt adhesive 12 000 cycles   D 260 g/m² natural rubberadhesive >20 000 cycles  

For the measurement of version 1, two plies of the above-described wovenPET filament fabric are fixed mechanically on the abrasion measurementapparatus and measured without an additional laminating adhesive. Theuse of the laminating adhesive in the case of version B produces nosignificant increase in abrasion resistance as compared with theadhesive-free base version 1.

Only when an interlayer of the invention is employed—in this example 120g/m² of a UV-crosslinked acrylate adhesive—is there an increase in theabrasion levels by more than 100%. A construction of this kind asversion 3 can be realized industrially without great effort bylaminating together two single-sided woven tapes each constructed from awoven PET backing with an adhesive coat weight of 60 g/m². The result isthe inventive backing assembly composed of the two woven outer layersand 2×60 g/m²=120 g/m² of adhesive as an interlayer in between. Thewoven PET tape coated on one side with 60 g/m² of acrylate adhesive hasan abrasion resistance of 1800 cycles, and so for the backing assemblyaccording to version 3 the corresponding abrasion value that could havebeen expected was 3600 cycles. In actual fact, however, it is possibleto increase the abrasion resistance by more than 300%.

In version 4 the interlayer used is a commercially availabledouble-sided carpet-laying tape (tesafix® 4964) consisting of about 250g/m² of a resin-modified natural rubber adhesive and a 110 g/m² wovenspun rayon fabric as central backing material. When subjected toabrasion measurement the double-sided adhesive tape gives a value ofonly about 500 cycles; in its function as an interlayer for the twowoven PET outer layers, the abrasion measurement on version 4 wasdiscontinued after 20 000 cycles without the backing assembly havingbeen abraded right through. In this combination as well the scuffresistance is improved by more than 300% in comparison with the sum ofthe individual values.

The absolute gain in abrasion resistance is even greater if a suitablefurther backing is additionally installed between the two woven PETfabric outer plies.

These may be films, foamed films, foams and in particular textilebackings. With version 3 from table 2 as the basis it is possible toproduce further highly abrasion-resistant backing assemblies if atextile backing is inserted centrally into the interlayer of 120 g/m²self-adhesive composition.

In technical terms this variant can also be realized in an extremelysimple way by laminating the textile backing in question between twoplies of the above-described woven PET tape with 60 g/m² self-adhesivecomposition (table 3). Since the two outer layers are already coatedwith sufficient self-adhesive composition, there is no need for separatefixing of the textile ply. The self-adhesive composition thereforefulfills the dual function of being an abrasion-promoting interlayer andof being a fixing aid for the centrally introduced textile. TABLE 3Construction of the backing assembly from 2 outer plies of a woven PETfabric (125 g/m²) Abrasion resistances and 60 g/m² acrylate adhesive and7 N 10 N a textile backing Applied weight 3 none  12 000 cycles   5100cycles 5 PET staple fiber web, 60 g/m² >20 000 cycles — 6 Woven filamentfabric, 60 g/m² >20 000 cycles — 7 Nylon fabric, 75 g/m²  34 400 cycles8 PET loop fabric, 230 g/m² >50 000 cycles 9 PET Multiknit, 320 g/m²— >23 000 cycles

Even nonwovens which lack inherent abrasion resistance, such as, forexample, a hydroentangled PET staple fiber web of 60 g/m² basis weight,which on its own is abraded right through after just 140 cycles,improves the abrasion resistance of the overall assembly according toversion 5 from 12 000 to more than 20 000 cycles. When inherently stabletextile backings are used centrally in the backing assembly (variants 7to 9 with a loop fabric, a nylon fabric and a Multiknit nonwoven,respectively), the abrasion measurement with an applied weight of 7 N isalready reaching its limits. An increase in the scuffing load by 10 Napplied weight produces more than 23 000 cycles even for variant 9,however. This puts assemblies of this kind in the regions which aremeasured for special abrasion protection components on cable looms, suchas braided hoses, fluted tubes, etc., and which offer maximumprotection. In particular, textiles made from toughened elastic orwear-resistant materials, such as polyamide, carbon fibers or glass, forexample, lead to further improvements in abrasion protection.

From the exemplary backing assemblies of tables 2 and 3 it is clearthat, with a corresponding construction of the backing material inaccordance with the invention, very high abrasion and scuff resistancesare achievable, so that adhesive tapes produced from such backings offeran attractive combination of bandaging and wrapping tape with integratedabrasion protection. Adhesive tapes of this kind are appropriateprimarily for the spiral and longitudinal sheathing of electrical linesto form cable sets when the latter are used on a long-term basis inareas where scuffing and vibration are hazards. In view of theirexcellent abrasion protection effect, however, backing assemblies ofthis kind possess general suitability as protective systems againstscuffing and rubbing stresses. The provision of self-adhesion, to forman adhesive tape, is not absolutely necessary if the positioning andfixing of the system at the area to be protected is achieved in anotherway: for example, by means of a stitched hose or a hose withtouch-and-close fastening around an elongate product requiringprotection.

The examples described below indicate to the skilled worker how suchassembly backings are produced.

EXAMPLE 1

For the outer layer a woven polyester filament fabric with a basis massof 125 g/m² is chosen which has 45 threads per cm in the warp directionand 25 threads per cm in the fill direction. The filament has a lineardensity of 167 dtex. The ultimate tensile strength measured is 220 N/cmin the breaking test with a breaking elongation of 32% in the warpdirection. This polyester fabric is coated onto the textile backingunder pressure and temperature by transferring 60 g/m² of aUV-crosslinked acrylate hotmelt (BASF acResin 258) from release paper,to form a single-sided woven adhesive tape.

-   a) for the backing assembly according to version 3 from table 2, two    plies of this single-sided woven adhesive tape are laminated to one    another with the adhesive. A self-adhesive wrapping tape can be    produced from this nonadhesive backing assembly by coating with    about 100 g/m² of the same acrylate hotmelt, with the possibility of    controlling the adhesive properties which are important for the    subsequent application, such as adhesion, cohesion, and tack, within    wide ranges by way of the extent of UV crosslinking.-   b) as in example 1 a), but in the course of the lamination of the    two single-sided outer plies a 0.25 mm thick hydroentangled PET    staple fiber web with a basis mass of 60 g/m² is laminated in as a    textile backing between the adhesive layers.

The abrasion values are listed in tables 2 and 3 as versions 3 and 5.

EXAMPLE 2

The woven PET filament fabric described in example 1 is used as theouter plies. As the viscoelastic interlayer the double-sided adhesivetape tesafix® 4964 is chosen, which is composed of a woven spun rayonfabric of about 110 g/m² with on either side about 120 to 130 g/m² of aresin-modified natural rubber adhesive. Laminating this system underpressure produces a highly abrasion-resistant assembly backing which canbe utilized as a backing for self-adhesive tapes or else, without anadhesive coating, can be used as abrasion protection (version 4 fromtable 2).

COUNTEREXAMPLE

The critical effect of the interlayer according to the invention in theincrease in abrasion resistance is evident from the followingcounterexample.

If the woven PET filament fabrics described in example 1 are used asouter layers but only a minimal amount of a heat-activable,thermoplastic laminating adhesive is used to form the assembly, theabrasion values which result from the overall assembly correspondvirtually only to the sum of the two outer layers (version 2 from table2). Additional protection is therefore not achieved.

1. A highly abrasion-resistant tape for bandaging cable harnesses inautomobiles, comprising a backing having a first outer layer A and asecond outer layer B, with an interlayer C located between and firmlyconnected, in each case over its entire surface, to the outer layers Aand B, the outer layers A and B being composed of a woven or formed-loopknit, the interlayer C being composed of a viscoelastic adhesive,self-adhesive, or a double-sided adhesive tape.
 2. The tape as claimedin claim 1, wherein the viscoelastic adhesive or the adhesives for thedouble-sided adhesive tape are self-adhesive compounds based on naturalrubber, synthetic rubber, polyacrylates or silicones.
 3. The tape asclaimed in claim 1, wherein the abrasion resistance of the backing(measured in accordance with ISO 6722, Section 9.3 “Scrape abrasionresistance”) is at least 150% of the sum of the abrasion resistances ofthe individual plies.
 4. The tape as claimed in claim 1, wherein theinterlayer C has a basis weight of 40 to 600 g/m², and/or a thickness of50 to 1000 μm.
 5. The tape as claimed in claim 1, wherein the wovenfabrics or formed-loop knits of outer layers A and B are composed offilaments or yarns of polyester, polyamide, glass fibers and/or carbonfibers.
 6. The tape as claimed in claim 1, wherein the interlayer C is adouble-sided adhesive tape with a film, web, paper or woven backingmaterial and with a double-sidedly applied viscoelastic adhesive layerof in each case 40 to 300 g/m².
 7. The tape as claimed in claim 1,wherein the backing is coated on at least one side with a self-adhesivecompound, it being possible for the self-adhesive compound to be arubber or acrylate or silicone adhesive.
 8. A method of wrapping anelongate product comprising guiding the tape as claimed in claim 1 in ahelical spiral around the elongate product.
 9. A method of wrapping anelongate product comprising sheathing the elongate product with the tapeas claimed in claim 1 in its axial direction.
 10. Elongate productwrapped with a tape as claimed in claim
 1. 11. A vehicle comprisingelongate product as claimed in claim 10.